[Analysis of clinicopathological features and prognosis of sporadic synchronous multiple primary colorectal cancers].

Objective: To investigate the impact of relative locations of multiple foci and microsatellite status of sporadic, synchronous, multiple, primary, colorectal carcinomas on clinicopathological features and prognosis. Methods: The clinicopathologic and prognostic data of 278 patients with sporadic, synchronous, multiple, primary, colorectal carcinomas who had been admitted to the Department of Colorectal Surgery at Zhejiang Cancer Hospital from January 2008 to July 2022 were retrospectively collected. The patients were categorized into three groups based on the relative locations of their multiple cancer foci: (1) a right-sided group that comprised patients with multiple cancer foci in the cecum, ascending colon, hepatic flexure of the colon, and transverse colon; (2) a left-sided group that comprised patients with multiple cancer foci in the splenic flexure of the colon, descending colon, sigmoid colon, and rectum; and (3) a left- and right-sided group that comprised patients with multiple cancer foci in the right half of the colon and left half of the colon/rectum. Additionally, the patients were further divided into two groups based on microsatellite status: a high microsatellite instability (MSI-H) and a low MSI/stable MSI (MSI/L&MSS) group. We compared differences in clinical characteristics and prognostic indicators between these groups. The χ2 test was utilized to compare selected clinical characteristics, whereas Kaplan-Meier survival analyses and log-rank tests were performed to compare their effects on prognosis. Result: Among 278 patients with SSCRC, 256 (92.1%) presented with two cancer foci and 22 (7.9%) with more than two foci. Additionally, 255 patients (91.7%) had adenocarcinomas, whereas the remaining 23 (8.3%) had mucinous adenocarcinomas. Lymph node metastases were identified in 136 patients (48.9%); the cancer foci had infiltrated beyond the muscular layer in 238 (85.6%); and 147 patients (52.9%) were diagnosed with TNM Stage III-IV disease. There were 155 patients (55.8%) in the left-sided group, 55 (19.8%) in the right-sided group, and 68 (24.5%) in the left- and right-sided group. Immunohistochemical examination of all four mismatch repair proteins were performed in 199 cases, revealing that 166 of these patients had MSI/L&MSS and 33 MSI-H disease. In the left-sided, left- and right-sided, and right-sided groups, the proportion of women was 16.8% (26/155), 26.5% (18/68), and 49.1% (27/55), respectively; these differences are statistically significant (χ2=22.335, P<0.001). The proportions of patients with more than three cancer foci were 5.2% (8/155), 16.2% (11/68), and 5.5% (3/55), respectively; these differences are statistically significant (χ2=8.438, P=0.015). The proportions of mucinous adenocarcinomas were 4.5% (7/155), 8.8% (6/68), and 18.2% (10/55), respectively; these differences are statistically significant (χ2=10.026, P=0.007). The proportions of patients with lymph node metastases were 55.5% (86/155), 48.5% (33/68), and 30.9% (17/55); these differences are statistically significant (χ2=9.817, P=0.007). The proportions of patients with Stage T3 & T4 disease in each group according to location were 81.3% (126/155), 88.2% (60/68), and 94.5% (52/55), respectively; these differences are statistically significant (χ2=6.293,P=0.043). The proportions of TNM Stage III-IV tumors were 59.4% (92/155), 54.4% (37/68), and 32.7% (18/55), respectively; these differences are statistically significant (χ2=11.637, P=0.003). Age, size of cancer foci, presence of distant metastasis, adenoma, nerve invasion, and vascular invasion did not differ significantly between the three groups (all P>0.05). Compared with those with MSI-H, patients with MSI/L&MSS disease were more likely to be aged >65 years and male (50.6% [84/166] vs. 15.2% [5/33], χ2=13.994,P<0.001; 80.7% [134/166] vs. 54.5% [18/33], χ2=10.457,P=0.001), more likely to be in the left-sided group (63.3% [105/166] vs. 24.2% [8/33], χ2=18.232, P<0.001), had a higher proportion of cancer foci of diameter <4 cm (54.8% [91/166] vs. 33.3% [11/33], χ2=5.086,P=0.024), and a lower proportion of mucinous adenocarcinomas (4.2% [7/166] vs. 27.3% [9/33], χ2=19.791,P<0.001), more likely to develop distant metastases (22.3% [37/166] vs. 6.1% [2/33], χ2=4.601,P=0.032), more likely to have lymph node metastases (57.2% [95/166) vs. 24.2% [8/33], χ2=11.996,P<0.001) and nerve invasion (28.9% [48/166] vs. 6.1% [2/33], χ2=7.643, P=0.006), had a higher proportion of TNM Stage III-IV disease (60.2% [100/166] vs. 24.2% [8/33], χ2=14.374, P<0.001), and a smaller proportion of family history of tumors (28.9% [48/166] vs. 60.6% [20/33], χ2=12.228, P<0.001). All the above-listed differences are statistically significant (all P<0.05). The differences in number of cancer foci, depth of infiltration, presence or absence of adenomas, and vascular invasion were not statistically significant (all P>0.05). In the 33 patients with MSI-H status and mismatch repair protein loss, the highest frequency of deletion was found in PMS-2 (66.7%, 22/33), followed by MLH-1 (57.6%, 19/33), whereas the proportions of MSH-2 (33.3%, 11/33) and MSH-6 (24.2%, 8/33) deletions were relatively low. There were statistically significant differences in the 3-year overall survival rates among the groups according to relative locations of cancer foci. The 3-year overall survival rates were 96.8%, 79.6%, and 88.5% in the right-sided, left- and right-sided, and left-sided groups, respectively (P=0.021). As to microsatellite status, the 3-year overall survival rate of patients with MSI-H disease was 93.8%, which is significantly better than the 78.4% for those with MSI/L & MSS (P=0.026). Conclusions: Among sporadic, synchronous, multiple, primary, colorectal carcinomas, those with right-sided disease had the deepest local infiltration, whereas those with left-sided disease had the greatest number of lymph node metastases, most advanced clinical TNM stage, lowest percentage of MSI-H disease, and the poorest prognosis.

The value of TRUS in the staging of rectal carcinoma before and after radiotherapy and comparison with the staging postoperative pathology.

AIM: To compare the effectiveness of transrectal ultrasonography (TRUS) with that of postoperative pathological examination in staging rectal carcinoma before surgery and before and after radiotherapy. MATERIALS AND METHODS: A prospective study was undertaken comprising 62 patients with stage T3 or T4 rectal carcinoma confirmed by endoscopic biopsy. RESULTS: TRUS showed significant differences (p < 0.01) in tumour echogenicity and volume, border delineation, local invasion, and draining lymph node involvement before and after radiotherapy, and significant reduction in blood flow resistance index after radiotherapy but no difference (p > 0.05) in the classification of tumour blood flow. In ultrasonographic assessments, 53 of the 62 cases (85.5%) showed lower T stages after radiotherapy. TRUS showed an accuracy of 94.1% for T2 cases, 77.3% for T3 cases, and 83.3% for T4 cases, and an overall accuracy of 87.1% in comparison with the results of postoperative pathological examination. CONCLUSION: TRUS is expected to play a vital role in the accurate preoperative staging of rectal carcinoma with the increasing utilization of adjuvant radiotherapy in rectal carcinoma and to contribute to the assessment of treatment.

Preparation and characterization of grafted collagen-multiwalled carbon nanotubes composites.

This paper describes a new class of composite materials designed by combining multiwalled carbon nanotubes (MWCNTs) and grafted collagen matrix. These materials show high mechanical capabilities by taking advantage of the favorable mechanical characteristics of MWCNTs. Furthermore, doping carbon nanotubes into grafted collagen matrix results in a substantial improvement of thermal stability and infrared emissivity. Thus these materials possess potential applications in some fields such as biomedicine and infrared camouflage.

Electrochemical behavior and detection of hepatitis B virus DNA PCR production at gold electrode.

Sequence-known short-stranded hepatitis B virus (HBV) DNA fragment (181 bps) was obtained by PCR method. The strategy for its electrochemical detection was designed by covalently immobilizing single-stranded HBV DNA on gold electrode surface via carboxylate ester as a linkage between 3'-hydroxy end of DNA and carboxyl group of thioglycolic acid (TGA) self-assembled monolayer. The hybridization reaction on surface was evidenced by electrochemical methods using ferrocenium hexafluorophosphate (FcPF6) as an electroactive indicator. The interactions of Fc+ with single-stranded (ss) and double-stranded (ds) HBV DNA immobilized on TGA monolayer were studied. The difference between the responses of Fc+ at ss- and ds-DNA/Au electrodes suggested that this hybridization biosensor could be conveniently used to monitor DNA hybridization with a high sensitivity. AC impedance and XPS techniques have been employed to characterize the immobilization of ss-DNA on the gold surface.

[Os(bpy)2(PVP)10Cl]Cl polymer and Nafion dual-film modified graphite electrode for the amperometric determination of trace amounts of norepinephrine.

A chemically modified graphite electrode was prepared by using a dual film of [Os(bpy)2(PVP)10Cl]Cl polymer and Nafion. The modified electrode showed excellent electrocatalytical activity for the oxidation of norepinephrine (NE) and an ability to eliminate efficiently the interference of ascorbic acid and other anions. The catalytic peak currents obtained from the cyclic voltammograms increased linearly with increasing concentration of NE. A log-log plot of catalytic current versus NE concentration showed a dual-linear relationship in the ranges 1.8 x 10(-8)-4.4 x 10(-6) M and 4.4 x 10(-6)-2.9 x 10(-4) M with correlation coefficients of 0.990 and 0.999, respectively. The detection limit was about 18 nM (3 delta). At a potential of +500 mV the chronoamperometric response showed a linear relationship between the steady state current and NE concentration in the range 1.3-130 microM. With a further increase in NE concentration a Michaelis-Menten-shaped response was observed. The apparent Michaelis-Menten constant and the maximum current were 1.7 mM and 86 microA, respectively. The modified electrode showed excellent reproducibility, sensitivity and stability for the determination of NE at trace levels.

Amperometric determination of lactate dehydrogenase based on a carbon fiber microcylinder electrode modified covalently with Toluidine Blue O by acylation.

A method has been developed for the modification of a carbon fiber microcylinder electrode with acylation. The stability and surface coverage of the Toluidine Blue O-modified microelectrode were studied by cyclic voltammetry. The modified electrode showed significant activity for the electrocatalytic oxidation of NADH in pH 6.8-7.8 solution. The catalytic current increased linearly with increasing concentration of NADH from 4.0 x 10(-5) to 1.5 x 10(-3) M. A simple amperometric determination based on electrochemical detection of NADH produced from the enzymatic reaction of lactate with NAD(+) under the catalysic effect of lactate dehydrogenase (LDH) is reported. The experimental factors which had primary influence on the analytical performance were studied. The sensor had a linear response over a range of LDH concentrations from 5.0 U l(-1) to 200 U l(-1) at -0.2 V vs. SCE under optimum conditions. A satisfactory result was obtained for the determination of LDH in clinical blood samples.